Eric Portenga
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drericp.bsky.social
Eric Portenga
@drericp.bsky.social
Geomorphologist and Quaternary Geologist on the Earth Science faculty at Eastern Michigan University

Landscapes • Erosion • Fire • Ice • Land use
Clear skies for the last few days means we can get out to do some #undergraduate #research on the Sturgis Moraine #Michigan, seeing whether we can reorient displaced #glacialerratics with a Schmidt Hammer 🪨 🔨 🧐

#geosciences #earthscience #geology #geomorphology #GreatLakes #EMU
November 4, 2025 at 5:38 PM
We made it! Today is the first day of the Great Lakes Earth Exchange guest speaker program at #EMU. 🥳 Ph.D. Candidate Ashley Scott from Western Michigan University is the first official member of the #GLEEClubEMU. Come hear her talk about Dolomite 🪨 at 2PM in 111 Strong Hall! #Geology #EarthScience
October 29, 2025 at 3:57 PM
Coming soon to #EMU, magnetic mineral separation!
🪨 🧲 ✨😍

#Geology
#EarthScience
#Magnets
#Research
October 22, 2025 at 6:50 PM
Got into the field this week for a new student project who is creating 3D scans of dated erratics and measuring them to see if there are metrics that help distinguish between moved and unmoved rocks!
#MichiganErratics
#GreatLakes
#GlacialGeology
#EarthScience
#Geology
#UndergraduateReeesrch
#EMU
October 18, 2025 at 7:10 PM
SO excited to announce the inaugural line-up of the #NSF funded Great Lakes #Earth Exchange speaker series (aka the #GLEEClubEMU) at #EasternMichiganUniversity. We've got talks on dolomitization, #groundwater modelling, #archaeology, and #GreatLakes water #chemistry. All are welcome to attend!
October 13, 2025 at 7:42 PM
The #EMU #EarthScience Support #Laboratory is getting a makeover! Unboxed our new jaw crusher, plate grinder, and ro-tap sieve shakers today! Soon, #geology faculty will be able to do mineral separation in house! Just waiting on the magnetic separator 🧲

🪨🪨🪨
September 11, 2025 at 2:59 AM
Brave the wind, and come on down! Check out the #EMU #Geography and #Geology Department table at #STEM Night at #Ypsilanti Community High School! See if you can complete the Rock Cycle, make jolly rancher stratigraphy, and put a 📍 on the Quaternary Map of #Washtenaw County! #EarthScience
September 5, 2025 at 8:09 PM
Happy #InternationalDogDay to Max, our derpy #dog, lover of #LakeMichigan, and occasional #fieldwork assistant. Unfortunately, he doesn’t have a good nose for finding #MichiganErratics
August 26, 2025 at 9:27 PM
No, I’m not testing #MichiganErratics for allergies. Dots are #SchmidtHammer measurements that reveal the relative hardness of #rock surfaces. Strong rock ➡️ short exposure; weak rock ➡️ long exposure. #geomorphology #geology #geochronology #GreatLakes
August 26, 2025 at 8:50 PM
When the going gets tough sampling super hard #rocks and you bend a solid steel chisel, you know it is time to call in help from #Wolverine! #MichiganErratics

#geology #earthscience #geomorphology #fieldwork #research #icesheet #Quaternaryscience #Michigan #GreatLakes
August 25, 2025 at 1:13 PM
Been back out in the field this week collecting nearly the rest of samples needed to date the Port Huron Moraine built by the Saginaw Lobe of the Laurentide #IceSheet. Hunting for #MichiganErratics in the “Thumb” of #Michigan has been hard because of centuries of farming and other land use
August 24, 2025 at 12:22 PM
Struck out hunting for #MichiganErratics today, but got to explore a small old growth #forest with black maple, huge beech, and 200-year old hemlock trees at the Caro Airport. Yet another reason why the #GreatLakes are awesome! (Unfortunately, not open to public)

#EarthScience #Fieldwork #Michigan
August 7, 2025 at 12:26 AM
Woohoo! First sample collected from the Port Huron #Moraine of the Saginaw Lobe of the Laurentide #IceSheet! How long ago? Guess we’ll find out in…oh…a year?! #Geology #Geomorphology #Research #MichiganErratics
August 2, 2025 at 1:33 AM
New #Geology & #EarthScience recruitment poster up in Strong Hall at #EMU. Hopefully this helps students decide to declare a Geo Major!
July 30, 2025 at 5:08 PM
Day 5: 🪨🪨🪨🪨🪨🪨🪨🪨🪨🪨

The first complete set of #MichiganErratics for my #NSF research project constraining Laurentide #IceSheet retreat through the #GreatLakes

1 down, 7 to go!

#Geology #EarthScience #Research #Michigan
July 26, 2025 at 1:04 AM
Day 4: Averaging 18,000 steps and covering hundreds of acres daily looking for #MichiganErratics. When I find them, I definitely don’t take them for granted (but they are #granite) 🪨

Ending my hunt on the Outer Port Huron #Moraine with this behemoth left as a gift by the Laurentide #IceSheet
July 25, 2025 at 12:05 AM
Day 3: @paul-bierman.bsky.social nice gneiss, eh? Migmatite send it your way in the first batch of #MichiganErratics! 🪨

#EarthScience #Geology #Rocks
July 23, 2025 at 1:36 PM
Day 2 of hunting for #MichiganErratics was less fulfilling…had to ask these turkeys if they knew were any were (they didn’t). At least I found a beautiful over the #ManisteeRiver at Eagle’s View, Springfield Twp. Park
July 23, 2025 at 12:59 AM
Yesterday was Day 1 on the Outer Port Huron #Moraine (Lake Michigan Lobe) hunting for #MichiganErratics! Collected 4 samples

#Geology #LaurentideIceSheet #EarthScience #Michigan #GreatLakes
July 23, 2025 at 12:57 AM
Yesterday was Day 1 on the Outer Port Huron #Moraine (Lake Michigan Lobe) hunting for #MichiganErratics! Collected 4 samples

#Geology #LaurentideIceSheet #EarthScience #Michigan #GreatLakes
July 23, 2025 at 12:57 AM
Finding more #MichiganErratics for #NSF #geology #research today on the #PortHuronMoraine in #TuscolaCounty #Michigan, including some BIG ROCKS!

Had some help from local farmers and wildlife
July 11, 2025 at 9:59 PM
Announcing the Great Lakes Earth Exchange (aka the #GLEEClub_EMU) at #EasternMichiganUniveristy. The GLEE Club will host 4 speakers each year for 4 years to visit our campus and share their Geoscience-related work with our undergrads. More details to come!

#GreatLakes #Geology #EarthScience
June 27, 2025 at 6:54 PM
Beating the high temps of this heat dome by checking out the stunning Black Hand Sandstone and #geomorphology of Ash Cave at Hocking Hills State Park with the family. Kiddos also got their first try at panning for “jewels” 😍

#Geology #EarthScience #Ohio
June 26, 2025 at 2:28 AM
First day out hunting for #MichiganErratics for my #NSF award reexamining the timing of #LaurentideIceSheet retreat from the #GreatLakes region. Not all are usable for #10Be dating, but they exist! Will be back up to the Outer Port Huron #Moraine in July to keep the search going #Geology #Research
June 11, 2025 at 2:38 PM
460’ above #LakeMichigan on the Inner Port Huron Moraine, first family trip to #SleepingBearDunes

Doing our bit to support our #NationalParkService and get the girls to their first park unit!

Found great limestone #MichiganErratics with rugose #fossils …but no quartz #Geology #Michigan #GreatLakes
June 7, 2025 at 9:08 PM